Planning something like a vacation, conference or wedding is difficult, as there are enormous amounts of variables, options, goals and other factors that can be considered when making the plan. For example, a wedding may require a site for the ceremony, a site for the reception, bridesmaid's dresses, available hotel accommodations for out of town visitors, and so forth, which need to be considered in view of factors such as cost, timing, proximity and so forth.
A person planning something along these lines may search the Internet to help get ideas and to start narrowing down the possible choices. However, the amount of content returned for a search can be overwhelming, and many times much of it is irrelevant or impractical to use. Further, while a human can recognize a relationship between the diverse concepts related to a wedding, such as reception sites and bridesmaid's dresses, search engines generally do not. Thus, multiple searches typically need to be performed to find desired content.
However, the field of planning is very diverse. The types and demographics of people who want to plan things are widely variable. Further, the search content that appeals to one user may vary greatly from that of another, due to different purposes/moods/attitudes of people, e.g., two people may want to vacation near the same place in California, but one person may want to plan a golf vacation, while the other wants to tour wineries.
It would be extremely expensive, and almost infeasible, for a single company to create enough logic to help automatically generate (even in part) the widely diverse numbers and types of plans that people would desire. At the same time, experts, mavens and people who have experienced or put together well-planned events may have a great deal of planning expertise with respect to various parameters and circumstances, but (except for expensive professionals) have no way to share that expertise except to possibly assist friends in making similar plans. Adding content to the internet such as posting blogs, pictures and the like may help others to an extent, but this does not really help in the planning process beyond providing ideas, and suffers from the same drawbacks as mentioned above, e.g., getting buried amongst large amounts of diverse content.